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At some point in the past, wolves started hanging out with humans and evolved into the first dogs. But when? And where? A new study of ancient fossils suggest that wolves may have befriended hunter-gatherers who were roaming around Europe 15 or 20,000 years ago. NPR's Nell Greenfieldboyce has this report on how scientists used new genetic tricks to look at old dogs.
NELL GREENFIELDBOYCE, BYLINE: Dogs were the first animal ever to be domesticated. And Robert Wayne says that's amazing because they're also the only large carnivore we ever tamed.
ROBERT WAYNE: When you start to dream about that and think, well, how could we actually take something that could kill us and it becomes our best friend and lives close with us, sleeping on our beds, but in the wild, these are aggressive animals that routinely take down prey larger than themselves. So that, I think, is a wonderful puzzle.
GREENFIELDBOYCE: Wayne has been trying to figure out when and where those dangerous meat eaters started to become our pals. He's a biologist at the University of California, Los Angeles. He says some people think that Fido first emerged in the Middle East or East Asia. That's what genetic studies of modern dogs and wolves have suggested. But then again, the earliest doggie fossils have been found in Europe.
Recently, Wayne and his colleagues got a hold of 18 samples from dog-like and wolf-like fossils. They were mostly from Europe and go back tens of thousands of years.
WAYNE: Some of these ancient dogs have very short faces, for instance, and are large, almost Great Dane size but they're clearly not like modern wolves.
GREENFIELDBOYCE: His team used cutting-edge techniques to extract DNA from the ancient bits of bone and teeth, then compared that ancient DNA to modern DNA from dogs of different breeds plus wolves and coyotes. What they found is that modern dogs were closely related to either ancient dogs or wolves from Europe or to modern European wolves.
WAYNE: So we really didn't have any other conclusion that we could make except that dogs seemed to be domesticated in Europe because all the mitochondrial DNA diversity that we found in modern dogs derives from European populations of wolves and dogs.
GREENFIELDBOYCE: In the journal Science, they report that the European domestication probably happened around 18 to 32,000 years ago. Wayne says that humans back then would've been hunter-gatherers who hunted large game. Wolf-like proto-dogs might have joined humans on their migrations, eating from carcasses that the hunters left behind and gradually becoming closer and closer to human society.
Elaine Ostrander has studied dog evolution at the National Human Genome Research Institute. She says this study is unique.
ELAINE OSTRANDER: It's really the first one to include ancient canines. And it doesn't just have one or two. They manage to have 18. So they're able to build a pretty good statistical argument. They really are.
GREENFIELDBOYCE: Do you think this is going to put an end to the debate?
OSTRANDER: Well, I think probably not entirely.
GREENFIELDBOYCE: This study looked at only a limited amount of DNA and there were no fossils from China, for example. So Ostrander thinks there's still fossils and DNA to be found that could add to the story.
OSTRANDER: And so I think it's not an end. I think it's a beginning.
GREENFIELDBOYCE: She predicts we'll learn a lot more about dogs and, in doing so, a lot more about ourselves. Nell Greenfieldboyce, NPR News.
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